The explosive growth of the Internet has resulted in huge numbers of web pages being published. Finding specific information among the billions of pages of information is facilitated by search engines, such as those provided by Google™ and Yahoo™, which use “web crawlers” to locate new or modified web pages. The content of these pages is analyzed, keywords are extracted from the pages, and the keywords are added to a search index, which links to a list of web pages that contain a particular word. A weight or rank for the web page can be generated on the basis of the number of times that word occurs on the web page, and stored in the index. A variety of other parameters can be factored into the web-page rank, including the number of times other search users have clicked on the link to that web page, how extensively that web page is linked to from other web pages, personal reviews and ratings of web pages or sites, or on the basis of an amount that a given web site is willing to pay for a particular ranking.
When a user types in a search word or term, the search engine performs a lookup of the search index and generates a result set of web pages that contain the search term. Web pages within this result set may then be organised in accordance with their respective rankings, and the highest-ranked results displayed to the user.
In most cases search queries are received from terminals that are fixedly connected to the Internet (either directly, or via one or several network portions), and of course the transmission of data within the Internet—on a per request basis—is free. With the advent of widespread deployment of 3G networks, search requests are increasingly being received from terminals connected to wireless networks. Unlike the transmission of data within fixed-line networks, the transmission of data within mobile networks is typically metered on a per transmission basis. As a result, mobile terminals are faced with hitherto unseen costs for accessing sites on the basis of search results generated by search engines.